Feasibility, safety and efficacy of laparoscopy and laparoscopy‐assisted vs. open surgery for acute small bowel obstruction in adults
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The objective of this review is to assess whether laparoscopic or laparoscopy‐assisted surgery is feasible and safe for acute small bowel obstruction, and if laparoscopic and laparoscopy‐assisted surgery present advantages compared to open surgery in terms of short‐term and long‐term outcomes.
Background
Acute intestinal obstruction is one of the most common surgical emergencies. The small bowel obstruction is the site of obstruction in most patients (76%) and adhesions are the most common etiology (65%) (Markogiannakis 2007). Postoperative intraabdominal adhesions are associated with significant rehospitalization rates and costs (Ray 1998). The first laparoscopic adhesiolysis for small bowel obstruction was performed by Clotteau (Clotteau 1990). Following this first case, laparoscopy has been used for treating small bowel obstruction by several investigators, because of its perceived advantages in selected cases. Laparoscopy in small bowel obstruction has no clear role yet; it may have a therapeutic as well as a diagnostic role. In several series laparoscopic or laparoscopy‐assisted surgery is suggested as a feasible and convenient moe of surgery for this condition; there is also reason to suspect both advantages and also difficulties and risks. Clinical series and comparative studies will be studied to assess feasibility, safety and efficacy in the short and the long term.
Objectives
The objective of this review is to assess whether laparoscopic or laparoscopy‐assisted surgery is feasible and safe for acute small bowel obstruction, and if laparoscopic and laparoscopy‐assisted surgery present advantages compared to open surgery in terms of short‐term and long‐term outcomes.
Methods
Criteria for considering studies for this review
Types of studies
Randomised controlled trials and non randomised controlled prospective trials evaluating laparoscopy and laparoscopy‐assisted surgery versus traditional open surgery for acute small bowel obstruction will be considered.
Types of participants
Adult (aged >16 yrs) patients who undergo surgery for a acute small bowel obstruction.
Types of interventions
All minimally invasive approach for acute small bowel obstruction will be compared with conventional open surgery
Types of outcome measures
Primary outcome:
short‐term (within 30 days of surgery) overall morbidity
Secondary outcomes:
1) the following specific, main complications within 30 days: any operative complication (bleeding, subphrenic or pelvic intraabdominal abscesses); any wound infectious complication; any respiratory complication (pulmonary embolism, pneumonia, pleural effusion, atelectasis, acute respiratory distress syndrome); any cardio‐vascular complication (acute coronary syndrome, myocardial infarction, deep vein thrombosis).
2) the following long‐term complications (after 30 days): adhesions requiring reintervention and incisional hernias.
3) re‐operations within 30 days.
4) readmissions within 30 days.
5) length of hospital stay.
6) duration of post‐operative ileus measured as days until first movel movement after surgery.
7) pain scores on day 1‐3.
8) 30‐day mortality.
9) hospital costs.
10) surgical (not anaesthetic) time.
11) conversion rate in laparoscopic arms.
12) procedures carried out during the operation (i.e. adhesiolysis, bowel resection, hernia repairs etc).
Search methods for identification of studies
We plan to search for published randomised and non randomised controlled trials without language restrictions using the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1950 onwards) and EMBASE (1980 onwards).
Searches will be carried out using medical subject headings (MeSH) and free text words in combination with the search strategy for randomised controlled trials reported.The proposed MEDLINE strategy (Ovid interface) is given below and will be modified when applied to other databases.
#1 (intestinal obstruction) or (small bowel obstruction) or (small near bowel near obstruction)
#2 MeSH descriptor Intestinal obstruction explode all trees
#3 (#1 OR #2)
#4 laparotom* or laparascop* or (abdominal surgery)
#5 MeSH descriptor laparotomy explode all trees
#6 MeSH descriptor laparoscopy explode all trees
#7 (#4 OR #5 OR #6)
#8 (#3 AND #7)
Data collection and analysis
We will conduct the review according to the recommendations of The Cochrane Collaboration (Higgins 2006) as well as the Cochrane Injuries Group. We will use Review Manager 5 to conduct the review.
Two authors (RC, JA) will assess titles or abstracts of all studies identified by the initial search and excluded clearly non‐relevant studies. Full text articles will be obtained for potentially relevant studies and any studies with unclear methodology. All these studies will be assessed by two authors as to whether they meet the inclusion criteria for this review, their method of randomisation and their adequacy of allocation concealment. Disagreements on inclusion will be resolved by in consensus and, if necessary, by scrutiny by an independent third author (AM).
The following information for each included trial will be extracted independently by the two investigators (JA, RC): method of outcome, blinding of outcome evaluators and balance of prognostic factors.
Methodological quality
JA and RC will register whether the authors of the trials used a sample size calculation, and whether or not they made their analysis using an intention‐to‐treat method. JA and RC will assess the methodological quality of each trial independently. Any unclear or missing information will be clarified by contacting the authors of the specific trial. Differences in opinion between the authors extracting data will be resolved through discussion. STM will serve as arbitrator in case difference in opinion persist.
Assessment of methodological quality of studies
JA and RC will assess the methodological quality of the trials independently, without masking of the trial names. The review authors will follow the instructions given in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2006) and the Cochrane Injuries Group. Due to the risk of biased overestimation of intervention effects in randomised trials with inadequate methodological quality (Kjaergard 2001; Moher 1998; Schulz 1995), the review authors will look at the influence of the methodological quality of the trials on the results by evaluating the reported randomisation and follow‐up procedures in each trial. If information is not available in the published trial, JA and RC will contact the authors in order to assess the trials correctly. The review authors will assess generation of allocation sequence, allocation concealment, blinding, and follow‐up.
Allocation concealment
Adequate: If centralised, or pre‐numbered containers administered serially to patients, or an on‐site computer with allocations in a locked unreadable file, or sequentially numbered sealed opaqueenvelopes.Unclear: If the trial is described as randomised, but failed to describe the method of allocation concealment.
Inadequate, if a completely transparent procedure was used for example, if case record numbers, dates of birth, or an open list of random numbers was used.
Allocation sequence generation
Adequate: If computer generated or random number table used.
Unclear: If the trial is described as randomised, but failed to describe the method of allocation sequence.
Inadequate: If patients were allocated according to names, dates, admittance numbers, etc. These are known as quasi‐randomised trials and will be excluded from the review.
Blinding
Adequate: If the trial was described as double blind.
Unclear: If the trial was described as double blind, but the method of blinding was not described.Not performed: If the trial was not double blind.
Measures of treatment effect
Dichotomous data will be analysed for relative risk ratio (RR), odds ratio (OR), and the absolute effects will be measured with the risk differences. 95% confidence intervals will be calculated for these measures of effect. Intention to treat analysis will be performed extracting the number of patients originally allocated to each treatment group irrespective of compliance. If numbers extracted by the two authors are different, differences will be resolved by a third author (FS). The Mantel‐Haenszel method will be used for the meta‐analysis (Mantel 1959; Greenland 1985). Results will be presented on a forest plot graph.
Trial investigators will be contacted if additional information is required.
Chi‐squared test will be used for heterogeneity assessment. If outcomes were measured with continuous scale, data of treatment effects will be analysed with weighted mean difference. Where different trials use different scales, the results will be standardised and then combined (i.e. standardised mean difference).
JA and RC will independently perform a sensitivity analysis at the end of the review by examining the trial inclusion criteria, reassessing excluded studies, re‐analysing data imputing, and re‐analysing data using the DerSimonian and Laird method (DerSimonian 1986).
